expression
are you alright?; are you OK?
A fixed expression used to ask if someone is safe or unharmed, often after an accident or trouble. The か makes it a direct question, typically in casual or concerned speech.
事故の後、彼は「無事か?」と聞いた。
After the accident, he asked, 'Are you alright?'
地震の直後、友達から「無事か?」とメッセージが来た。
Right after the earthquake, I got a message from a friend asking, 'Are you OK?'